Digital cameras are electronic devices that capture digital images and save them to a digital memory. Multiple images may be captured and stored. The stored images may be later printed, copied, transferred, displayed, etc.
The size of captured images may vary, and image sizes depend heavily on the size of the image sensor in terms of the number of pixels it contains. The image sensor size typically ranges from 1.3 Megapixels (Mp) to 5 Mp. The higher the number of pixels, the higher the resolution of the captured image obtained by the sensor. The resulting image file is about 50 kilobytes to about 2 megabytes in size. A common image file size created by a 2 megabyte pixel image sensor is about 700 kilobytes. However, image files will undoubtedly grow larger as image sensor size grows. The image sensor size may grow in order to improve image resolution (i.e., as manufacturers produce image sensors made of more and more pixel sensor elements).
A digital camera user generally downloads captured images to a computer storage medium or transmits image files to a printer, and may print and/or store the images for subsequent use. Some advantages of digital images are that they may be transmitted electronically to others, may be used numerous times, and may be copied and modified. One transmission example is transmission of images via electronic mail (e-mail), wherein the user may wish to send photographs to geographically distant friends and relatives. E-mail transmission offers the advantages of being nearly instantaneous, low in cost, and relatively trouble free. The recipient may print, store, manipulate, or re-transmit a received digital image.
In the prior art, image transmission has typically comprised transmitting images as they are captured. The prior art approach is to e-mail or otherwise transmit an image as is.
The image transmission approach of the prior art has several drawbacks. The image transmission may be relatively slow if image files are large and may take significant time to transfer. The problem is not as acute for users who have high speed network access. However, many people are still using slow transmission methods, such as modems and phone lines. Over a 28.8 kilobaud phone line, a single image may take several minutes to transmit via e-mail.
An alternative prior art approach is to convert an image into a smaller image in order to facilitate transmission. One example is the conversion of a captured image into a thumbnail image. Thumbnail images are typically 140×120 pixels in size. However, thumbnails are too small for proper viewing and do not contain sufficient image detail. In addition, although a user may be able to use an available image processing software application to change the image size and resolution, many users do not have such image processing software or may not know how to use such software. Moreover, many users do not want to take the time to perform such an operation even if they are capable of doing so. Such processing may be too complex for most users. Most users just want to send an image and not bother with any additional steps.
Therefore, there remains a need in the art for improvement to image handling for purposes of image transmission.